In vanilla, the Safari Zone is post-Clair. Here, it’s accessible before Whitney (3rd gym). More importantly, Drayano added daily swarm mechanics to the Safari Zone, rotating rare Pokémon like Riolu, Beldum, and Larvitar on specific weekdays.
The Johto Safari Zone has been fully unlocked from the start (no waiting for specific Baoba calls). The six zones now contain specific themes: Pokemon Sacred Gold And Storm Silver Pokemon Locations
Munchlax Note: This is the only location to catch Munchlax before the post-game. Use Honey on the trees in the Meadow zone. Pokémon Sacred Gold and Storm Silver — Pokémon